Abstract 17151: Selective Stimulation of Renal Sympathetic Nerves Increases Stellate Ganglion Nerve Activity and Ventricular Arrhythmias After Myocardial Infarction in Canine
Backgroud: Renal sympathetic nerves (RSN) play a key role in conditions associated with systemic sympathetic hyperactivity. Cardiac sympathetic nerve (especially the left stellate ganglion (LSG)) overactivity contributes to the pathogenesis of ventricular arrhythmias (VA) after acute myocardial infarction (AMI). The present study investigated the effect of RSN stimulation on LSG activity and VA incidence after AMI in canine.
Methods: Twenty-seven dogs received 3-hour continuous left-sided selective stimulation of RSN (SS-RSN group, n=9), sham stimulation of RSN (Sham group, n=8) or LSG ablation (LSG-A) plus 3-hour SS-RSN (LSG-A group, n=10) were included. AMI was induced by ligating the proximal left anterior descending coronary artery. SS-RSN were performed using high frequency stimulation (20 Hz, 0.1 ms) via an electrode placed on the adventitia of left renal artery at 10% below the voltage required to increase the systolic blood pressure (BP). LSG function was evaluated by voltage-blood pressure response curve of LSG stimulation. BP, ventricular effective refractory period (ERP), indices of heart rate variablity (HRV), serum norepinephrine (NE) and LSG function were measured at baseline and after 3-hour SS-RSN. The incidence of VA was determined during 1-hour recording after AMI was induced. The expression of C-Fos and NGF protein in LSG was detected in SS-RSN group and Sham group.
Results: Compared with baseline, 3-hour SS-RSN induced a significant increase in BP, sympathetic nerve indices of HRV, serum NE level and a decrease in ERP at all recording sites (all p<0.05). The BP elevation response induced by LSG stimulation was significantly enhanced by 3-hour SS-RSN. The incidence of VA in SS-RSN group was significantly higher than that in sham group or LSG-A group (p<0.05). Spontaneous VF occurred in 7/9, 1/8, and 2/10 dogs in the SS-RSN, sham and LSG-A group, respectively (p<0.05). SS-RSN group showed a significant increase in the expression of C-Fos and NGF protein in LSG compared with sham group.
Conclusions: Three-hour SS-RSN increases LSG activity and facilitates VA incidence after AMI. LSG ablation significantly inhibits the incidence of VA, indicating that LSG plays an important role in SS-RSN-induced ventricular arrhythmogenesis.
- © 2013 by American Heart Association, Inc.